Mold for compound ingots.



No. 638,909. Patented Dec. l2, I899. S. A. COSGRAVE.

MOLD FOR COMPOUND INGOTS.

(Appliabion filed Sept. 1, 1899.)

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No: 638,909. Patented Dec. l2, i899. s. A. COSGRAVE.

mow FOR COMPOUND INGOTS.

(Application filed Sept. 1, 1899.)

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SYLVESTER A. COSGRAVE, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO MARIAB. COSGRAVE, OF SAME PLACE, AND AARON FRENCH AND MARGARET L. PATTERSON,OF PITTSBURG, PENNSYLVANIA.

MOLD FOR COMPOUND INGOTS.

SPECIFICATION forming part of Letters Patent No. 638,909, dated December12, 1899- Application filed September 1. 1899. Serial No. 729,164. (Nomodel.)

To all whom it may concern:

Be it known that I, SYLVESTER A. Cos- GRAVE, a citizen of the UnitedStates, residing at Edgewood Park, in the countyof Allegheny and Stateof Pennsylvania, have invented or discovered certain new and usefulImprovements in Molds for Compound Ingots,of which improvements thefollowing isaspecification.

The invention described herein relates to certain improvements inapparatus for the practice of the inventions described and claimed inapplications, Serial Nos. 714,952 and 729,163, filed, respectively,April 29 and September 1,- 1899. The inventions set forth in saidapplications consist, generally stated, in casting one kind or grade ofmetal against a mold-wall formed in part at least of a material whichwill eliminate or prevent the formation of any oXid or other elementalchange which might prevent an intimate union of such metal with anothermetal, removing such mold-wall, and then casting another kind or gradeof metal against the prepared surface.

The object of the present invention is to provide for the manufacture ofcompound ingots having their central or interior portions formed of onekind or grade of metal which is surrounded or inclosed by another gradeor kind of metal.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification,Figure 1 is a sectional elevation of an ingot-mold having a core inposition and showing one kind or grade of metal cast around the core.Fig. 2 is a horizontal section of the same. Figs. 3 and .4 are views,respectively similar to Figs. 1 and 2, showing the core removed and thespace occupied by the core filled with another kind or grade of metal.Fig. 5 is a sectional elevation of a mold constructed to permit of thecasting of the metal through the bottom of the mold, and Fig. 6 is asimilar view showing the core partially withdrawn and the space soformed filled with metal.

In the practice of my invention the ingotmold 1 is of the usual or anydesired shape, with its walls preferably slightly inclined outwardlyfrom the top down, so as to facilitate the removal of the mold from theingot. This mold is supported, as is customary, on the stool 2, and thecore is arranged within the mold. It will be understood that if a 5 5greater thickness of metal is desired on one side of the core than onthe other the core can be placed eccentrically within the mold.

The method set forth in the applications referred to can be effected byallowing the metal first cast to solidify sufficiently to permit of theremoval of the mold and the foreing out of the core in any manner, thenreheating the hollow ingot, placing it on a stool or plate, and thencasting the other metal into 6 5 the heated ingot. It is preferred toeffect the removal of the core just as quick as a sufficiently-thickskin has formed around the core to retain the still molten metal of theinterior of the ingot and immediately casting the other metal into thematrix thus formed. By this method the high heat of the two bodiesseparated by the thin wall of solidified but still highly-heated metalwill be melted, thereby permitting an interdiffusion of thecharacteristics of the two metals. To this end the core 3 is formedaround a lifting-rod 4:, which has a supporting and removing plate 5secured to its lower end. The core should be so formed on the supportingand remov- 8o ing plate as to entirely protect the latter from contactwith the molten metal first cast. This protection is preferably effectedby making the supporting and removing plate slightly smaller than thecore, as shown in Fig. 1, and providing a socket 6 in the stool for thereception of the supporting and removing plate. This socket is madesufficiently deep to permit the edges of the core projecting outside ofthe supporting and removing plate 0 to rest upon the stool.

By the employment of a supporting and removing plate slightly smallerthan the core, which is formed of or coated with a fiuxing ordeoxidizing material, as set forth inthe specifications referred to, aconsiderable quantity of such material will be left on the surface ofthe metal as cast, as is desirable for reasons stated in saidapplications.

After the core 3 has been placed in position I00 in the mold one kind orgrade of metal, as high-carbon steel, is cast around the core. As soonas a sufficiently-thick skin is formed around the core to retain theinterior metal, which is still molten, the core is removed by pulling upon the rod 4 and the other metal immediately cast into the spaceoccupied by the core 3. WVhile not necessary, it is preferred to place atile 7 of fire-clay or other refractory material in the socket in thestool.

In order to prevent as far as possible any exposure to atmosphericinfluences of the wall uncovered by the removal of the core, a pourgate8 is connected to a passage 9 through the stool of the mold, the outletof each passage being located so as to be covered by the core during thecasting of the first metal. If the second metal be poured into the gate8 as the core is being Withdrawn, there will not be any materialexposure of the surface uncovered by the removal of the core. If thesecond metal be so poured as to closely follow the core as it iswithdrawn, the core may be with drawn earlier, as the in flowing metalwill support the shell formed on the surface of the metal first cast.

As the metal in the wall of the annular ingot first formed is molten andas the thin skin formed against the core is at a high temperature whenthe second metal is cast, the retaining skin or shelL-being very thinandinclosed between two bodies of molten metal, will become molten, thusaffording an opportunity to unite intimately, so that thecharacteristics of one metal will modify those of the other for aconsiderable distance on each side of the plane of union. Hence therewill not be a sharp line of demarcation between the two metals, but agradual merging of the characteristics of one metal into those of theother.

I claim herein as my invention- 1. The combination of a mold, a corehaving its exterior portion formed by a friable material, a supportingand removing plate at one end of the core, said supporting and removingplate having a smaller periphery than the core, and means'for removingthe supporting and removing plate through the annular body of metalformed around the core, substantially as set forth.

2. The combination of a mold, a supporting and removing plate, apull-rod attached to the plate and a core formed around the rod andresting on the plate, the exterior portion of the core being formed of afriable material, and extending beyond the edges of the supporting andremoving plate, substantially as set forth.

3. The combination of an open topped mold provided with an inlet at itslower end, a core covering said inlet, and means for withdrawing saidcore, thereby uncovering said inlet, substantially as set forth.

In testimony whereof I have hereunto set my hand.

SYLVESTER A. COSGRAVE.

Witnesses:

DARWIN S. WOLCOTT, M. S. MURPHY.

